Fixed the behavior of JMP (ind) in sim65 when it runs with the 6502X CPU type. #2547
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… with the "6502X" CPU type. The JMP (ind) bug is present in the 6502 which is emulated by both the "6502" and "6502X" emulation targets of sim65; specifically, the OPC_6502_6C handler. In the old code, the bug-exhibiting code was not executed when the target was set to 6502X, which is incorrect. the patch removes the (CPU == CPU_6502) check, which made no sense. The JMP (ind) bug was actually fixed in the 65c02. Indeed, the OPC_65C02_6C opcode handler has code that implements the 'right' behavior.
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When touching the code anyway, I would suggest to fix the brace style in the piece of code you changed. It doesn't match the one described in the wiki. |
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The prescribed coding style hasn't been applied consistently throughout the file. It's a bit of a mess in that respect. In this particular function, the bracketing style is left as it was to keep the patch minimal relative to the issue it's addressing, which I think is good practice. Commits (and PRs) should aim to fix precisely one issue, in my opinion. If making the coding style consistent is a goal, that warrants a separate issue, with separate patches to fix precisely and only those coding style consistency issues. |
yes indeed. don't mix style fixes with code fixes |
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Thanks! |
The JMP (ind) bug is present in the 6502 which is emulated by both the "6502" and "6502X" emulation targets of sim65; specifically, the OPC_6502_6C handler. In the old code, the bug-exhibiting code was not executed when the target was set to 6502X, which is incorrect. The patch removes the (CPU == CPU_6502) check, which made no sense.
The JMP (ind) bug was actually fixed in the 65c02. Indeed, the OPC_65C02_6C opcode handler has code that implements the 'right' behavior.